Fire extinguishing apparatus comprising a buoyant hose



Jan. 10, 1967 L. e. A. ERIKSSON 3,297,093

FIRE EXTIN GUISHING APPARATUS COMPRISING A BUOYAI JT HO$E Filed May 27 1965 l A'- "'1, I 7

' i N 21 a" 8 1 fi I Q 1. I q 4 1 N V EN TOR. 1 419s 621s 7:41 44 0596 flea m0 BY w United States Patent 3,297,093 FIRE EXTiNGUlElHlNG APPARATUS COMPRESING A BUOYANT HOSE Lars Gustav Anders Eriksson, Solna, Sweden, assignor to Svenska Skumslacknings Aktieholaget, a corporation of Sweden Filed May 27, 1965, Ser. No. 459,337 Claims priority, application Sweden, Feb. 23, 1965, 2,310/ 65 '7 Claims. (Cl. 169--4) This invention relates to a fire extinguishing apparatus for tanks or other reservoirs for storing inflammable liquid substances and comprising a hose which is folded up in readiness in a magazine disposed in the reservoir or communicating therewith so as to be in contact with the inflammable liquid, and having an inlet for a fire extinguishing agent, preferably foam. In case of fire in the tank the hose has to be unfolded out of the magazine and has to rise to the surface of the liquid in the tank so that fire extinguishing agent can pass through a supply pipe to the magazine and therefrom up to the seat of fire to extinguish the fire. As a rule, the magazine is disposed within the tank in an inaccessible position and therefore has to be opened entirely automatically under the action of the pressure of the fire extinguishing agent supplied to the magazine and the hose. The object of the invention is to provide a device by means of which the magazine is infallibly opened in case of fire.

In its broadest aspect the invention is in that the magazine has an opening through which the hose can be unfolded so as to be able to rise through the inflammable liquid, said opening being normally sealed by a diaphragm which because of the nature of its material, kerfs, thickness or other factors influencing its strength is adapted to burst at an internal pressure considerably lower than the external pressure exerted on the diaphragm by the inflammable liquid in the reservoir when the reservoir is filled to its maximum level. Preferably, the diaphragm is adapted to burst at an internal pressure of 3-30 feet of water and to withstand an external pressure of about 60 feet of water. The diaphragm may be very thin and of low strength if it is sustained on its inner side by a disc or similar support which lies loose in the opening of the magazine so as to be readily thrown off as the magazine is to be opened. The diaphragm may be retained at its margin by means of a clamping ring and may further be externally protected by a cap adapted to be thrown off.

An embodiment of the invention is described hereinbelow with reference to the annexed drawing in which FIG. 1 is an elevation of an apparatus comprising a device according to the invention, FIG. 2 is an enlarged vertical sectional view of the upper part of the hose magazine belonging to the apparatus, and FIG. 3 is a plan of a quadrant of the diaphragm.

Referring to FIG. 1 the chain-dotted lines indicate a lower part of the circumferential wall and the bottom of a tank for storing inflammable liquid substances. Extending through the wall of the tank is a supply pipe for a fire extinguishing agent, preferably fire extinguishing foam. The supply pipe terminates within the tank and is connected to a short piece of pipe, the end of which supports a magazine 12 adapted to contain a hose in a folded state. The lower open end of the hose is secured to the lower part of the magazine and is open toward the pipe 10, whereas the upper end 14 of the hose shown in FIG. 2 may be closed or open. A by-pass 16 or so called shock pipe extends from the pipe 10 to the upper part of the magazine 12. The upper opening 18 of the magazine is covered by a thin diaphragm 20, the inner side of which is supported by a plate or disc 22 which lies loosely on a shoulder 24 extending around the opening lid. A connecting flange 26 disposed around the opening of the magazine forms a support for the margin of the diaphragm 20 outside the disc 22. The diaphragm is held down on the upper surface of the flange 26 by a clamping ring 28 which is secured to the flange 26 by means of screws 39. A gasket 32 is inserted between the ring 28 and the diaphragm.

The diaphragm and its connecting means may be shielded outwardly from the tank by means of a protective cap 34, and the rim of the cap directed toward the flange 26 may be provided with an elastic sealing ring 36 which is tongueshaped in cross-section. This sealing ring may be replaced by another additional packing such as an O-ring. The diaphragm is made of a material of a thickness or strength such that it will burst at an internal pressure in the magazine that is considerably lower than the external pressure exerted on the diaphragm by the inflammable liquid in the reservoir when the reservoir for the inflammable liquid is filled to its maximum level. By way of example the diaphragm may be adapted to burst at an internal pressure of 330 feet of water and to withstand an external pressure of about 60 feet of water due to the support given to it by the disc 22.

Upon supply under pressure of fire extinguishing agent, such as foam, through the pipe, the foam or the air in the pipe lll ahead of the foam will build up an increasing pressure in the device. When the pressure transmitted to the upper end of the magazine via the by-pass 16 is increased to a value somewhat higher than the external liquid pressure, the diaphragm 20 will be deflected upwards and in certain cases the loose disc 22 will be lifted. As soon as the internal pressure becomes equal to the external liquid pressure plus the pressure required to rupture the diaphragm, the diaphragm will burst resulting in a decompression. At the same time the protective cap 34, if any, will be thrown off. The fire extinguishing agent also enters the hose in the magazine and unfolds the hose which will move upwards through the now uncovered opening it of the magazine, and according as the hose is filled with fire extinguishing agent it will rise in the liquid in the tank to the surface of the liquid and flow out on said surface to extinguish the fire.

The invention is not limited to the embodiment illustrated and described. Within the scope of the invention the clamping ring 28 for the diaphragm 20 may be provided with a threaded flange and screwed onto the connecting flange 26 instead of being secured by means of screws. In order to ensure that the diaphragm will burst at the desired internal pressure, it may have a circular or otherwise designed kerf 33 (FIG. 3). Instead thereof the material and the thickness of the diaphragm may be suitably adapted for this purpose. By way of example, the diaphragm may consist of glass or an acrylic plastics material which is resistant to the action of the inflammable liquid stored in the tank, in which case an annular groove may be provided in the upper surface of the diaphragm. Alternatively, the diaphragm may be in the form of a thin foil of a fluoric plastics material, such as polytetrafluoro ethylene (Teflon) without kerfs or grooves but so thin than it will burst at the calculated internal pressure. Due to the supportprovided by the underlying disc the diaphragm can withstand considerably higher pressures from the liquid in the tank.

What I claim is:

l. A fire extinguishing apparatus for tanks and other reservoirs for storing inflammable liquid to levels including a maximum level, comprising a magazine disposed in the reservoir below the maximum level thereof and provided with an inlet for a fire extinguishing agent and an outlet opening, a diaphragm normally closing said outlet opening, a hose having its one end open toward said inlet and its other end closed, said hose being folded in the magazhie in a state of readiness to be developed by the fire extinguishing agent to be introduced into the hose through the inlet end thereof, a diaphragm closing said outlet opening and thus normally preventing development of the hose, said diaphragm being of a nature to burst at an interior pressure in the magazine lower than the exterior pressure exerted on the diaphragm by the inflammable liquid in the reservoir when the latter is filled with inflammable liquid to the maximum level.

2. Apparatus as claimed in claim 1 and further characterized by the fact that said diaphragm is constructed to burst at an interior pressure in the magazine of 33() feet of water and to withstand an exterior pressure of about 60 feet of water.

3. Apparatus as claimed in claim 1 and further comprising a support mounted loosely in the outlet opening of the magazine, said diaphragm being of low strength and sustained at its inner side by said support.

4. Apparatus as claimed in claim 1 and further characterized by a mounting surface marginally encircling the outlet opening of the magazine, said diaphragm engaging said mounting surface at its margin, a clamping ring engaging said diaphragm and screw means pressing said clamping ring against said margin of the diaphragm to hold it in position over the outlet opening of the magazine.

5. Apparatus as claimed in claim l and further characterized by a mounting surface on the magazine encirc- [it ling the outlet opening thereof and engaged by one side of said diaphragm, a peripherally screw-threaded clamping ring engaging the other side of the diaphragm to hold it in position with its marginal portion squeezed between said ring and said mounting surface.

6. Apparatus as claimed in claim 1 and further c0mprising a protective cap engaging the outlet end of the magazine to protect the diaphragm, said cap being mounted loosely to be thrown off as the diaphragm is bursting.

7. Apparatus as claimed in claim 1 and further comprising a flanged portion of the magazine forming the outlet end thereof, a mounting surface formed on said portion and encircling the outlet opening of the magazine, said surface being engaged by one side of the margin of the diaphragm, a clamping ring engaging the other side of the margin of the diaphragm, a protective cap mounted loosely over the outlet end of the magazine and said ring to protect the diaphragm, and a peripheral packing member adapted to form an additional seal between the cap and said flanged portion.

References Cited by the Examiner UNITED STATES PATENTS EVERETT W. KIRBY, Primary Examiner. 

1. A FIRE EXTINGUISHING APPARATUS FOR TANKS AND OTHER RESERVOIRS FOR STORING INFLAMMABLE LIQUID TO LEVELS INCLUDING A MAXIMUM LEVEL, COMPRISING A MAGAZINE DISPOSED IN THE RESERVOIR BELOW THE MAXIMUM LEVEL THEREOF AND PROVIDED WITH AN INLET FOR A FIRE EXTINGUISHING AGENT AND AN OUTLET OPENING, A DIAPHRAGM NORMALLY CLOSING SAID OUTLET OPENING, A HOSE HAVING ITS ONE END OPEN TOWARD SAID INLET AND ITS OTHER END CLOSED, SAID HOSE BEING FOLDED IN THE MAGAZINE IN A STATE OF READINESS TO BE DEVELOPED BY THE FIRE EXTINGUISHING AGENT TO BE INTRODUCED INTO THE HOSE THROUGH THE INLET END THEREOF, A DIAPHRAGM CLOSING SAID OUTLET OPENING AND THUS NORMALLY PREVENTING DEVELOPMENT OF THE HOSE, SAID DIAPHRAGM BEING OF A NATURE TO BURST AT AN INTERIOR PRESSURE IN THE MAGAZINE LOWER THAN THE EXTERIOR PRESSURE EXERTED ON THE DIAPHRAGM BY THE INFLAMMABLE LIQUID IN THE RESERVOIR WHEN THE LATTER IS FILLED WITH INFLAMMABLE LIQUID TO THE MAXIMUM LEVEL. 